Seasonal changes of proximate composition and fatty acids of farmed dusky grouper (Epinephelus marginatus Lowe, 1834)

Summary The aim of this work was to determine the seasonality of nutrient profiles of dusky grouper (Epinephelus marginatus Lowe, 1834) cultured in a cage to improve knowledge on its nutritional composition. Fish (n = 735) were reared in a circular polyethylene floating cage for a 19-month experimental period and provided a commercial pelleted feed once a day with a total daily ration of 1% wet body weight. Fish were sampled every 3–4 months, and biometric parameters as well as muscle composition were determined. The edible proportion of fish increased slightly with culture time. The flesh showed low lipid content, similar to those reported for wild grouper. Biometric indices, muscle proximate composition and fatty acid profiles were significantly affected by seasonality, that is lipids and monounsaturated fatty acids increased during summer, in parallel with the decline of polyunsaturated fatty acids.